Rename global "labels" config option to "external_labels".

cmd/prometheus/main.go

@@ -206,6 +206,10 @@ func reloadConfig(filename string, rls ...Reloadable) (success bool) {
 	conf, err := config.LoadFile(filename)
 	if err != nil {
 		log.Errorf("Couldn't load configuration (-config.file=%s): %v", filename, err)
+		// TODO(julius): Remove this notice when releasing 0.17.0 or 0.18.0.
+		if err.Error() == "unknown fields in global config: labels" {
+			log.Errorf("NOTE: The 'labels' setting in the global configuration section has been renamed to 'external_labels' and now has changed semantics (see release notes at https://github.com/prometheus/prometheus/blob/master/CHANGELOG.md). Please update your configuration file accordingly.")
+		}
 		return false
 	}
 	success = true

config/config.go

@@ -274,7 +274,7 @@ type GlobalConfig struct {
 	// How frequently to evaluate rules by default.
 	EvaluationInterval Duration `yaml:"evaluation_interval,omitempty"`
 	// The labels to add to any timeseries that this Prometheus instance scrapes.
-	Labels model.LabelSet `yaml:"labels,omitempty"`
+	ExternalLabels model.LabelSet `yaml:"external_labels,omitempty"`
 
 	// Catches all undefined fields and must be empty after parsing.
 	XXX map[string]interface{} `yaml:",inline"`
@@ -292,7 +292,7 @@ func (c *GlobalConfig) UnmarshalYAML(unmarshal func(interface{}) error) error {
 
 // isZero returns true iff the global config is the zero value.
 func (c *GlobalConfig) isZero() bool {
-	return c.Labels == nil &&
+	return c.ExternalLabels == nil &&
 		c.ScrapeInterval == 0 &&
 		c.ScrapeTimeout == 0 &&
 		c.EvaluationInterval == 0

config/config_test.go

@@ -32,7 +32,7 @@ var expectedConf = &Config{
 		ScrapeTimeout:      DefaultGlobalConfig.ScrapeTimeout,
 		EvaluationInterval: Duration(30 * time.Second),
 
-		Labels: model.LabelSet{
+		ExternalLabels: model.LabelSet{
 			"monitor": "codelab",
 			"foo":     "bar",
 		},

config/testdata/conf.good.yml

@@ -4,7 +4,7 @@ global:
   evaluation_interval: 30s
   # scrape_timeout is set to the global default (10s).
 
-  labels:
+  external_labels:
     monitor: codelab
     foo:     bar
 

config/testdata/labelname.bad.yml

@@ -1,3 +1,3 @@
 global:
-  labels:
+  external_labels:
     not$allowed: value

config/testdata/labelname2.bad.yml

@@ -1,3 +1,3 @@
 global:
-  labels:
+  external_labels:
     'not:allowed': value

config/testdata/unknown_attr.bad.yml

@@ -4,7 +4,7 @@ global:
   evaluation_interval: 30s
   # scrape_timeout is set to the global default (10s).
 
-  labels:
+  external_labels:
       monitor: codelab
       foo:     bar
 

notification/notification.go

@@ -88,9 +88,9 @@ type NotificationHandler struct {
 	notificationsQueueLength   prometheus.Gauge
 	notificationsQueueCapacity prometheus.Metric
 
-	globalLabels model.LabelSet
-	mtx          sync.RWMutex
-	stopped      chan struct{}
+	externalLabels model.LabelSet
+	mtx            sync.RWMutex
+	stopped        chan struct{}
 }
 
 // NotificationHandlerOptions are the configurable parameters of a NotificationHandler.
@@ -151,7 +151,7 @@ func (n *NotificationHandler) ApplyConfig(conf *config.Config) bool {
 	n.mtx.Lock()
 	defer n.mtx.Unlock()
 
-	n.globalLabels = conf.GlobalConfig.Labels
+	n.externalLabels = conf.GlobalConfig.ExternalLabels
 	return true
 }
 
@@ -162,7 +162,7 @@ func (n *NotificationHandler) sendNotifications(reqs NotificationReqs) error {
 
 	alerts := make([]map[string]interface{}, 0, len(reqs))
 	for _, req := range reqs {
-		for ln, lv := range n.globalLabels {
+		for ln, lv := range n.externalLabels {
 			if _, ok := req.Labels[ln]; !ok {
 				req.Labels[ln] = lv
 			}

storage/remote/remote.go

@@ -30,9 +30,9 @@ import (
 
 // Storage collects multiple remote storage queues.
 type Storage struct {
-	queues       []*StorageQueueManager
-	globalLabels model.LabelSet
-	mtx          sync.RWMutex
+	queues         []*StorageQueueManager
+	externalLabels model.LabelSet
+	mtx            sync.RWMutex
 }
 
 // ApplyConfig updates the status state as the new config requires.
@@ -41,7 +41,7 @@ func (s *Storage) ApplyConfig(conf *config.Config) bool {
 	s.mtx.Lock()
 	defer s.mtx.Unlock()
 
-	s.globalLabels = conf.GlobalConfig.Labels
+	s.externalLabels = conf.GlobalConfig.ExternalLabels
 	return true
 }
 
@@ -102,7 +102,7 @@ func (s *Storage) Append(smpl *model.Sample) {
 	snew = *smpl
 	snew.Metric = smpl.Metric.Clone()
 
-	for ln, lv := range s.globalLabels {
+	for ln, lv := range s.externalLabels {
 		if _, ok := smpl.Metric[ln]; !ok {
 			snew.Metric[ln] = lv
 		}

web/federate.go

@@ -80,13 +80,13 @@ func (h *Handler) federation(w http.ResponseWriter, req *http.Request) {
 				Name:  proto.String(string(ln)),
 				Value: proto.String(string(lv)),
 			})
-			if _, ok := h.globalLabels[ln]; ok {
+			if _, ok := h.externalLabels[ln]; ok {
 				globalUsed[ln] = struct{}{}
 			}
 		}
 
 		// Attach global labels if they do not exist yet.
-		for ln, lv := range h.globalLabels {
+		for ln, lv := range h.externalLabels {
 			if _, ok := globalUsed[ln]; !ok {
 				protMetric.Label = append(protMetric.Label, &dto.LabelPair{
 					Name:  proto.String(string(ln)),

web/web.go

@@ -67,8 +67,8 @@ type Handler struct {
 	options     *Options
 	statusInfo  *PrometheusStatus
 
-	globalLabels model.LabelSet
-	mtx          sync.RWMutex
+	externalLabels model.LabelSet
+	mtx            sync.RWMutex
 }
 
 // ApplyConfig updates the status state as the new config requires.
@@ -77,7 +77,7 @@ func (h *Handler) ApplyConfig(conf *config.Config) bool {
 	h.mtx.Lock()
 	defer h.mtx.Unlock()
 
-	h.globalLabels = conf.GlobalConfig.Labels
+	h.externalLabels = conf.GlobalConfig.ExternalLabels
 
 	return true
 }